WASHINGTON (AP) — The Obama administration has finalized regulations that will force automakers to nearly double the average gas mileage of all new cars and trucks they sell by 2025.

The rules mean that all new vehicles would have to get an average of 54.5 miles per gallon in 13 years, up from 28.6 mpg at the end of last year. The requirements will be phased in gradually between now and then, and automakers could be fined if they don’t comply.

The regulations, announced Tuesday, will change the cars and trucks sold in U.S. showrooms, with the goal of slashing greenhouse gas emissions and fuel consumption. Automakers will need to improve gasoline-powered engines, and sell more alternative fuel vehicles. Critics say the rules will make cars unaffordable by adding thousands of dollars to the sticker price.

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